The December 2010 lunar eclipse occurred from 5:27 to 11:06 UTC on December 21 2010, coinciding with the date of the December solstice. It was visible in its entirety as a total lunar eclipse in North and South America, Iceland, Ireland, Britain and northern Scandinavia.

This eclipse occurred at the descending node of the moon's orbit. Lunar eclipses are always paired with a solar eclipse either 2 weeks before or after at new moon in the opposite node. In this case, it was followed by a partial solar eclipse at the ascending node on January 4, 2011, visible from Europe, northern Africa, and western Asia.

A saros series lasts for many centuries and has a similar event every 18 years and 11 days. This eclipse is the 18th of 26 total lunar eclipses in lunar saros series 125. The previous occurrence was on December 9, 1992, and the next will occur on December 31, 2028.

These simulated views of the earth from the center of the moon during the lunar eclipse show where the eclipse is visible on earth.

In North America, the eclipse was visible in its entirety on December 21, 2010, from 12:27 a.m. to 6:06 a.m. Eastern Standard Time.[6] In the Central Standard Time zone and west, the eclipse began the night of December 20.[7] Observers along South America's east coast missed the late stages of the eclipse because they occurred after moon-set.[8]

Likewise much of Europe and Africa experienced moon-set while the eclipse was in progress. In Europe, only those observers in northern Scandinavia (including Iceland), Ireland and Britain could observe the entire event. For observers in eastern Asia the moon rose in eclipse. The eclipse was not visible from southern and eastern Africa, the Middle East or South Asia. In Japan and northeastern Asia, the eclipse's end was visible, with the moon rising at sunset. In the Philippines it was observable as a partial lunar eclipse just after sunset.[8]

Predictions suggested that the total eclipse may appear unusually orange or red, as a result of the eruption of Mount Merapi in Indonesia on October 26.[9]

The lunar year series repeats after 12 lunations or 354 days (Shifting back about 10 days in sequential years). Because of the date shift, the Earth's shadow will be about 11 degrees west in sequential events.

The Metonic cycle repeats nearly exactly every 19 years and represents a Saros cycle plus one lunar year. Because it occurs on the same calendar date, the earth's shadow will be in nearly the same location relative to the background stars.

Lunar saros series 125, repeating every 18 years and 11 days, has 26 total lunar eclipses. The first was on June 17, 1704 and the last will be on March 19, 2155. The longest totality occurrence of this series (7th) was on August 22, 1812 when totality lasted one hour and 42 minutes.[11]